[PATCH v3 0/3] sun8i-a83t: Add touchscreen support on TBS A711

[PATCH v3 0/3] sun8i-a83t: Add touchscreen support on TBS A711

[Mylène Josserand]

Hello everyone,

This is a V3 of the patch series that adds touchscreen support
(FocalTech EDT-FT5x06 Polytouch) for TBS A711 (Allwinner sun8i-a83t SoC).
Based on last master of linux-input tree.

Since I can't test the suspend/resume functions there is no updates in
this series about factory/normal mode.

Changes since v2:
   - Remove the check if regulator is NULL (Dmitry Torokhov's review)
   - Add EPROBE_DEFER error not to print a error message (Lothar Waßmann's review)
   - Add set wake/reset on suspend/resume.
Changes since v1:
   - Remove patches 01 and 02 as Chen-Yu Tsai sent a similar patch:
   https://patchwork.kernel.org/patch/10111431/
   and it is merged on last next-20171222.
   (See commit f066f46ce5a5 "ARM: dts: sun8i: a83t: Add I2C device nodes and pinmux settings")
   - Update regulator according to Dmitry Torokhov's review: remove "optional"
   suffix while retrieving the regulator, rename it into "vcc" instead of
   "power" and add bindings documentation.
   - Update device tree according to Maxime Ripard's review: remove the
   label and rename the node.
   - Squash patch 03 with patch 05 to add I2C0 and touchscreen's node
   in one patch (see patch 02).

Patch 01: Add support for regulator in the FocalTech touchscreen driver
because A711 tablet is using a regulator to power-up the touchscreen.
Patch 02: Add a set wake/reset values on resume and suspend.
Patch 03: Add i2c0 and touchscreen's node for A711 TBS tablet.

Thank you in advance for any review.
Best regards,
Mylène

Mylène Josserand (3):
  Input: edt-ft5x06 - Add support for regulator
  Input: edt-ft5x06 - Set wake/reset values on resume/suspend
  arm: dts: sun8i: a83t: a711: Add touchscreen node

 .../bindings/input/touchscreen/edt-ft5x06.txt      |  1 +
 arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts          | 16 +++++++++
 drivers/input/touchscreen/edt-ft5x06.c             | 41 ++++++++++++++++++++++
 3 files changed, 58 insertions(+)

-- 
2.11.0

[PATCH v3 1/3] Input: edt-ft5x06 - Add support for regulator

[Mylène Josserand]

Add the support of regulator to use it as VCC source.

Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
---
 .../bindings/input/touchscreen/edt-ft5x06.txt      |  1 +
 drivers/input/touchscreen/edt-ft5x06.c             | 29 ++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt b/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
index 025cf8c9324a..48e975b9c1aa 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
+++ b/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
@@ -30,6 +30,7 @@ Required properties:
 Optional properties:
  - reset-gpios: GPIO specification for the RESET input
  - wake-gpios:  GPIO specification for the WAKE input
+ - vcc-supply:  Regulator that supplies the touchscreen
 
  - pinctrl-names: should be "default"
  - pinctrl-0:   a phandle pointing to the pin settings for the
diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
index 1e18ca0d1b4e..aa94494b06b5 100644
--- a/drivers/input/touchscreen/edt-ft5x06.c
+++ b/drivers/input/touchscreen/edt-ft5x06.c
@@ -39,6 +39,7 @@
 #include <linux/input/mt.h>
 #include <linux/input/touchscreen.h>
 #include <linux/of_device.h>
+#include <linux/regulator/consumer.h>
 
 #define WORK_REGISTER_THRESHOLD		0x00
 #define WORK_REGISTER_REPORT_RATE	0x08
@@ -91,6 +92,7 @@ struct edt_ft5x06_ts_data {
 	struct touchscreen_properties prop;
 	u16 num_x;
 	u16 num_y;
+	struct regulator *vcc;
 
 	struct gpio_desc *reset_gpio;
 	struct gpio_desc *wake_gpio;
@@ -991,6 +993,22 @@ static int edt_ft5x06_ts_probe(struct i2c_client *client,
 
 	tsdata->max_support_points = chip_data->max_support_points;
 
+	tsdata->vcc = devm_regulator_get(&client->dev, "vcc");
+	if (IS_ERR(tsdata->vcc)) {
+		error = PTR_ERR(tsdata->vcc);
+		if (error != -EPROBE_DEFER)
+			dev_err(&client->dev, "failed to request regulator: %d\n",
+				error);
+		return error;
+	}
+
+	error = regulator_enable(tsdata->vcc);
+	if (error < 0) {
+		dev_err(&client->dev, "failed to enable vcc: %d\n",
+			error);
+		return error;
+	}
+
 	tsdata->reset_gpio = devm_gpiod_get_optional(&client->dev,
 						     "reset", GPIOD_OUT_HIGH);
 	if (IS_ERR(tsdata->reset_gpio)) {
@@ -1120,20 +1138,31 @@ static int edt_ft5x06_ts_remove(struct i2c_client *client)
 static int __maybe_unused edt_ft5x06_ts_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
+	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
 
 	if (device_may_wakeup(dev))
 		enable_irq_wake(client->irq);
 
+	regulator_disable(tsdata->vcc);
+
 	return 0;
 }
 
 static int __maybe_unused edt_ft5x06_ts_resume(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
+	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
+	int ret;
 
 	if (device_may_wakeup(dev))
 		disable_irq_wake(client->irq);
 
+	ret = regulator_enable(tsdata->vcc);
+	if (ret < 0) {
+		dev_err(dev, "failed to enable vcc: %d\n", ret);
+		return ret;
+	}
+
 	return 0;
 }
 
-- 
2.11.0

[PATCH v3 2/3] Input: edt-ft5x06 - Set wake/reset values on resume/suspend

[Mylène Josserand]

On resume and suspend, set the value of wake and reset gpios
to be sure that we are in a know state after suspending/resuming.

Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
---
 drivers/input/touchscreen/edt-ft5x06.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
index aa94494b06b5..b013d97006e6 100644
--- a/drivers/input/touchscreen/edt-ft5x06.c
+++ b/drivers/input/touchscreen/edt-ft5x06.c
@@ -1143,6 +1143,12 @@ static int __maybe_unused edt_ft5x06_ts_suspend(struct device *dev)
 	if (device_may_wakeup(dev))
 		enable_irq_wake(client->irq);
 
+	if (tsdata->wake_gpio)
+		gpiod_set_value(tsdata->wake_gpio, 0);
+
+	if (tsdata->reset_gpio)
+		gpiod_set_value(tsdata->reset_gpio, 1);
+
 	regulator_disable(tsdata->vcc);
 
 	return 0;
@@ -1157,6 +1163,12 @@ static int __maybe_unused edt_ft5x06_ts_resume(struct device *dev)
 	if (device_may_wakeup(dev))
 		disable_irq_wake(client->irq);
 
+	if (tsdata->wake_gpio)
+		gpiod_set_value(tsdata->wake_gpio, 1);
+
+	if (tsdata->reset_gpio)
+		gpiod_set_value(tsdata->reset_gpio, 0);
+
 	ret = regulator_enable(tsdata->vcc);
 	if (ret < 0) {
 		dev_err(dev, "failed to enable vcc: %d\n", ret);
-- 
2.11.0

[PATCH v3 3/3] arm: dts: sun8i: a83t: a711: Add touchscreen node

[Mylène Josserand]

Tha A711 tablet has a FocalTech EDT-FT5x06 Polytouch touchscreen.
It is connected via I2C0. The reset line is PD5, the interrupt
line is PL7 and the VCC supply is the ldo_io0 regulator.

Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
---
 arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts b/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
index 1537ce148cc1..dc7b94a6c068 100644
--- a/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
+++ b/arch/arm/boot/dts/sun8i-a83t-tbs-a711.dts
@@ -156,6 +156,22 @@
 	status = "okay";
 };
 
+&i2c0 {
+	clock-frequency = <400000>;
+	status = "okay";
+
+	touchscreen@38 {
+		compatible = "edt,edt-ft5x06";
+		reg = <0x38>;
+		interrupt-parent = <&r_pio>;
+		interrupts = <0 7 IRQ_TYPE_EDGE_FALLING>;
+		reset-gpios = <&pio 3 5 GPIO_ACTIVE_LOW>;
+		vcc-supply = <&reg_ldo_io0>;
+		touchscreen-size-x = <1024>;
+		touchscreen-size-y = <600>;
+	};
+};
+
 &mmc0 {
 	vmmc-supply = <&reg_dcdc1>;
 	pinctrl-names = "default";
-- 
2.11.0

Re: [PATCH v3 1/3] Input: edt-ft5x06 - Add support for regulator

[Ondřej Jirman]

Hello Mylène,

On Wed, Jul 18, 2018 at 08:27:17PM +0200, Mylène Josserand wrote:
> Add the support of regulator to use it as VCC source.
> 
> Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
> ---
>  .../bindings/input/touchscreen/edt-ft5x06.txt      |  1 +
>  drivers/input/touchscreen/edt-ft5x06.c             | 29 ++++++++++++++++++++++
>  2 files changed, 30 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt b/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
> index 025cf8c9324a..48e975b9c1aa 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
> +++ b/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
> @@ -30,6 +30,7 @@ Required properties:
>  Optional properties:
>   - reset-gpios: GPIO specification for the RESET input
>   - wake-gpios:  GPIO specification for the WAKE input
> + - vcc-supply:  Regulator that supplies the touchscreen
>  
>   - pinctrl-names: should be "default"
>   - pinctrl-0:   a phandle pointing to the pin settings for the
> diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
> index 1e18ca0d1b4e..aa94494b06b5 100644
> --- a/drivers/input/touchscreen/edt-ft5x06.c
> +++ b/drivers/input/touchscreen/edt-ft5x06.c
> @@ -39,6 +39,7 @@
>  #include <linux/input/mt.h>
>  #include <linux/input/touchscreen.h>
>  #include <linux/of_device.h>
> +#include <linux/regulator/consumer.h>
>  
>  #define WORK_REGISTER_THRESHOLD		0x00
>  #define WORK_REGISTER_REPORT_RATE	0x08
> @@ -91,6 +92,7 @@ struct edt_ft5x06_ts_data {
>  	struct touchscreen_properties prop;
>  	u16 num_x;
>  	u16 num_y;
> +	struct regulator *vcc;
>  
>  	struct gpio_desc *reset_gpio;
>  	struct gpio_desc *wake_gpio;
> @@ -991,6 +993,22 @@ static int edt_ft5x06_ts_probe(struct i2c_client *client,
>  
>  	tsdata->max_support_points = chip_data->max_support_points;
>  
> +	tsdata->vcc = devm_regulator_get(&client->dev, "vcc");
> +	if (IS_ERR(tsdata->vcc)) {
> +		error = PTR_ERR(tsdata->vcc);
> +		if (error != -EPROBE_DEFER)
> +			dev_err(&client->dev, "failed to request regulator: %d\n",
> +				error);
> +		return error;
> +	}
> +
> +	error = regulator_enable(tsdata->vcc);
> +	if (error < 0) {
> +		dev_err(&client->dev, "failed to enable vcc: %d\n",
> +			error);
> +		return error;
> +	}
> +
>  	tsdata->reset_gpio = devm_gpiod_get_optional(&client->dev,
>  						     "reset", GPIOD_OUT_HIGH);
>  	if (IS_ERR(tsdata->reset_gpio)) {
> @@ -1120,20 +1138,31 @@ static int edt_ft5x06_ts_remove(struct i2c_client *client)
>  static int __maybe_unused edt_ft5x06_ts_suspend(struct device *dev)
>  {
>  	struct i2c_client *client = to_i2c_client(dev);
> +	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
>  
>  	if (device_may_wakeup(dev))
>  		enable_irq_wake(client->irq);
>  
> +	regulator_disable(tsdata->vcc);
> +

How will the touchscreen wakeup the system with interrupt if you power it off
on suspend? Perhaps guard this with device_may_wakeup() too? 

>  	return 0;
>  }
>  
>  static int __maybe_unused edt_ft5x06_ts_resume(struct device *dev)
>  {
>  	struct i2c_client *client = to_i2c_client(dev);
> +	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
> +	int ret;
>  
>  	if (device_may_wakeup(dev))
>  		disable_irq_wake(client->irq);
>  
> +	ret = regulator_enable(tsdata->vcc);
> +	if (ret < 0) {
> +		dev_err(dev, "failed to enable vcc: %d\n", ret);
> +		return ret;
> +	}
> +

Ditto.

Regards,
  o.

>  	return 0;
>  }
>  
> -- 
> 2.11.0
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH v3 1/3] Input: edt-ft5x06 - Add support for regulator

[Rob Herring]

On Wed, Jul 18, 2018 at 08:27:17PM +0200, Mylène Josserand wrote:
> Add the support of regulator to use it as VCC source.
> 
> Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
> ---
>  .../bindings/input/touchscreen/edt-ft5x06.txt      |  1 +

Please add acks when posting new versions.

>  drivers/input/touchscreen/edt-ft5x06.c             | 29 ++++++++++++++++++++++
>  2 files changed, 30 insertions(+)

Re: [PATCH v3 1/3] Input: edt-ft5x06 - Add support for regulator

[Dmitry Torokhov]

On Thu, Jul 19, 2018 at 12:46:45AM +0200, Ondřej Jirman wrote:
> Hello Mylène,
> 
> On Wed, Jul 18, 2018 at 08:27:17PM +0200, Mylène Josserand wrote:
> > Add the support of regulator to use it as VCC source.
> > 
> > Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
> > ---
> >  .../bindings/input/touchscreen/edt-ft5x06.txt      |  1 +
> >  drivers/input/touchscreen/edt-ft5x06.c             | 29 ++++++++++++++++++++++
> >  2 files changed, 30 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt b/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
> > index 025cf8c9324a..48e975b9c1aa 100644
> > --- a/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
> > +++ b/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
> > @@ -30,6 +30,7 @@ Required properties:
> >  Optional properties:
> >   - reset-gpios: GPIO specification for the RESET input
> >   - wake-gpios:  GPIO specification for the WAKE input
> > + - vcc-supply:  Regulator that supplies the touchscreen
> >  
> >   - pinctrl-names: should be "default"
> >   - pinctrl-0:   a phandle pointing to the pin settings for the
> > diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
> > index 1e18ca0d1b4e..aa94494b06b5 100644
> > --- a/drivers/input/touchscreen/edt-ft5x06.c
> > +++ b/drivers/input/touchscreen/edt-ft5x06.c
> > @@ -39,6 +39,7 @@
> >  #include <linux/input/mt.h>
> >  #include <linux/input/touchscreen.h>
> >  #include <linux/of_device.h>
> > +#include <linux/regulator/consumer.h>
> >  
> >  #define WORK_REGISTER_THRESHOLD		0x00
> >  #define WORK_REGISTER_REPORT_RATE	0x08
> > @@ -91,6 +92,7 @@ struct edt_ft5x06_ts_data {
> >  	struct touchscreen_properties prop;
> >  	u16 num_x;
> >  	u16 num_y;
> > +	struct regulator *vcc;
> >  
> >  	struct gpio_desc *reset_gpio;
> >  	struct gpio_desc *wake_gpio;
> > @@ -991,6 +993,22 @@ static int edt_ft5x06_ts_probe(struct i2c_client *client,
> >  
> >  	tsdata->max_support_points = chip_data->max_support_points;
> >  
> > +	tsdata->vcc = devm_regulator_get(&client->dev, "vcc");
> > +	if (IS_ERR(tsdata->vcc)) {
> > +		error = PTR_ERR(tsdata->vcc);
> > +		if (error != -EPROBE_DEFER)
> > +			dev_err(&client->dev, "failed to request regulator: %d\n",
> > +				error);
> > +		return error;
> > +	}
> > +
> > +	error = regulator_enable(tsdata->vcc);
> > +	if (error < 0) {
> > +		dev_err(&client->dev, "failed to enable vcc: %d\n",
> > +			error);
> > +		return error;
> > +	}
> > +
> >  	tsdata->reset_gpio = devm_gpiod_get_optional(&client->dev,
> >  						     "reset", GPIOD_OUT_HIGH);
> >  	if (IS_ERR(tsdata->reset_gpio)) {

You need to disable regulator here. We do not have
devm_regulator_enable() (and Mark had some concerns about mixing managed
and unmanaged APIs for regulators so we can't simply introduce it),
so I'd recommend using devm_add_action_or_reset() and iunstall custom
action to turn off regulator.

> > @@ -1120,20 +1138,31 @@ static int edt_ft5x06_ts_remove(struct i2c_client *client)
> >  static int __maybe_unused edt_ft5x06_ts_suspend(struct device *dev)
> >  {
> >  	struct i2c_client *client = to_i2c_client(dev);
> > +	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
> >  
> >  	if (device_may_wakeup(dev))
> >  		enable_irq_wake(client->irq);
> >  
> > +	regulator_disable(tsdata->vcc);
> > +
> 
> How will the touchscreen wakeup the system with interrupt if you power it off
> on suspend? Perhaps guard this with device_may_wakeup() too? 

Exactly, it should be in an "else" branch.

Thanks.

-- 
Dmitry

Re: [PATCH v3 1/3] Input: edt-ft5x06 - Add support for regulator

[Mylène Josserand]

Hello,

On Fri, 20 Jul 2018 07:43:55 -0600
Rob Herring <robh@kernel.org> wrote:

> On Wed, Jul 18, 2018 at 08:27:17PM +0200, Mylène Josserand wrote:
> > Add the support of regulator to use it as VCC source.
> > 
> > Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
> > ---
> >  .../bindings/input/touchscreen/edt-ft5x06.txt      |  1 +  
> 
> Please add acks when posting new versions.

Yes, sorry, I missed it. I will be more careful, next time.

Best regards,

-- 
Mylène Josserand, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH v3 1/3] Input: edt-ft5x06 - Add support for regulator

[Mylène Josserand]

Hello,

Thank you for your review.

On Thu, 19 Jul 2018 00:46:45 +0200
Ondřej Jirman <megous@megous.com> wrote:

> Hello Mylène,
> 
> On Wed, Jul 18, 2018 at 08:27:17PM +0200, Mylène Josserand wrote:
> > Add the support of regulator to use it as VCC source.
> > 
> > Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
> > ---
> >  .../bindings/input/touchscreen/edt-ft5x06.txt      |  1 +
> >  drivers/input/touchscreen/edt-ft5x06.c             | 29 ++++++++++++++++++++++
> >  2 files changed, 30 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt b/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
> > index 025cf8c9324a..48e975b9c1aa 100644
> > --- a/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
> > +++ b/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
> > @@ -30,6 +30,7 @@ Required properties:
> >  Optional properties:
> >   - reset-gpios: GPIO specification for the RESET input
> >   - wake-gpios:  GPIO specification for the WAKE input
> > + - vcc-supply:  Regulator that supplies the touchscreen
> >  
> >   - pinctrl-names: should be "default"
> >   - pinctrl-0:   a phandle pointing to the pin settings for the
> > diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
> > index 1e18ca0d1b4e..aa94494b06b5 100644
> > --- a/drivers/input/touchscreen/edt-ft5x06.c
> > +++ b/drivers/input/touchscreen/edt-ft5x06.c
> > @@ -39,6 +39,7 @@
> >  #include <linux/input/mt.h>
> >  #include <linux/input/touchscreen.h>
> >  #include <linux/of_device.h>
> > +#include <linux/regulator/consumer.h>
> >  
> >  #define WORK_REGISTER_THRESHOLD		0x00
> >  #define WORK_REGISTER_REPORT_RATE	0x08
> > @@ -91,6 +92,7 @@ struct edt_ft5x06_ts_data {
> >  	struct touchscreen_properties prop;
> >  	u16 num_x;
> >  	u16 num_y;
> > +	struct regulator *vcc;
> >  
> >  	struct gpio_desc *reset_gpio;
> >  	struct gpio_desc *wake_gpio;
> > @@ -991,6 +993,22 @@ static int edt_ft5x06_ts_probe(struct i2c_client *client,
> >  
> >  	tsdata->max_support_points = chip_data->max_support_points;
> >  
> > +	tsdata->vcc = devm_regulator_get(&client->dev, "vcc");
> > +	if (IS_ERR(tsdata->vcc)) {
> > +		error = PTR_ERR(tsdata->vcc);
> > +		if (error != -EPROBE_DEFER)
> > +			dev_err(&client->dev, "failed to request regulator: %d\n",
> > +				error);
> > +		return error;
> > +	}
> > +
> > +	error = regulator_enable(tsdata->vcc);
> > +	if (error < 0) {
> > +		dev_err(&client->dev, "failed to enable vcc: %d\n",
> > +			error);
> > +		return error;
> > +	}
> > +
> >  	tsdata->reset_gpio = devm_gpiod_get_optional(&client->dev,
> >  						     "reset", GPIOD_OUT_HIGH);
> >  	if (IS_ERR(tsdata->reset_gpio)) {
> > @@ -1120,20 +1138,31 @@ static int edt_ft5x06_ts_remove(struct i2c_client *client)
> >  static int __maybe_unused edt_ft5x06_ts_suspend(struct device *dev)
> >  {
> >  	struct i2c_client *client = to_i2c_client(dev);
> > +	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
> >  
> >  	if (device_may_wakeup(dev))
> >  		enable_irq_wake(client->irq);
> >  
> > +	regulator_disable(tsdata->vcc);
> > +  
> 
> How will the touchscreen wakeup the system with interrupt if you power it off
> on suspend? Perhaps guard this with device_may_wakeup() too? 

True, thank you for pointing it out.

> 
> >  	return 0;
> >  }
> >  
> >  static int __maybe_unused edt_ft5x06_ts_resume(struct device *dev)
> >  {
> >  	struct i2c_client *client = to_i2c_client(dev);
> > +	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
> > +	int ret;
> >  
> >  	if (device_may_wakeup(dev))
> >  		disable_irq_wake(client->irq);
> >  
> > +	ret = regulator_enable(tsdata->vcc);
> > +	if (ret < 0) {
> > +		dev_err(dev, "failed to enable vcc: %d\n", ret);
> > +		return ret;
> > +	}
> > +  
> 
> Ditto.

ack

> 
> Regards,
>   o.
> 
> >  	return 0;
> >  }
> >  
> > -- 
> > 2.11.0
> > 
> > 
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel  


Best regards,

-- 
Mylène Josserand, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH v3 1/3] Input: edt-ft5x06 - Add support for regulator

[Mylène Josserand]

Hello Dmitry,

Thank you for your review!

On Mon, 23 Jul 2018 15:39:26 -0700
Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:

> On Thu, Jul 19, 2018 at 12:46:45AM +0200, Ondřej Jirman wrote:
> > Hello Mylène,
> > 
> > On Wed, Jul 18, 2018 at 08:27:17PM +0200, Mylène Josserand wrote:  
> > > Add the support of regulator to use it as VCC source.
> > > 
> > > Signed-off-by: Mylène Josserand <mylene.josserand@bootlin.com>
> > > ---
> > >  .../bindings/input/touchscreen/edt-ft5x06.txt      |  1 +
> > >  drivers/input/touchscreen/edt-ft5x06.c             | 29 ++++++++++++++++++++++
> > >  2 files changed, 30 insertions(+)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt b/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
> > > index 025cf8c9324a..48e975b9c1aa 100644
> > > --- a/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
> > > +++ b/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt
> > > @@ -30,6 +30,7 @@ Required properties:
> > >  Optional properties:
> > >   - reset-gpios: GPIO specification for the RESET input
> > >   - wake-gpios:  GPIO specification for the WAKE input
> > > + - vcc-supply:  Regulator that supplies the touchscreen
> > >  
> > >   - pinctrl-names: should be "default"
> > >   - pinctrl-0:   a phandle pointing to the pin settings for the
> > > diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
> > > index 1e18ca0d1b4e..aa94494b06b5 100644
> > > --- a/drivers/input/touchscreen/edt-ft5x06.c
> > > +++ b/drivers/input/touchscreen/edt-ft5x06.c
> > > @@ -39,6 +39,7 @@
> > >  #include <linux/input/mt.h>
> > >  #include <linux/input/touchscreen.h>
> > >  #include <linux/of_device.h>
> > > +#include <linux/regulator/consumer.h>
> > >  
> > >  #define WORK_REGISTER_THRESHOLD		0x00
> > >  #define WORK_REGISTER_REPORT_RATE	0x08
> > > @@ -91,6 +92,7 @@ struct edt_ft5x06_ts_data {
> > >  	struct touchscreen_properties prop;
> > >  	u16 num_x;
> > >  	u16 num_y;
> > > +	struct regulator *vcc;
> > >  
> > >  	struct gpio_desc *reset_gpio;
> > >  	struct gpio_desc *wake_gpio;
> > > @@ -991,6 +993,22 @@ static int edt_ft5x06_ts_probe(struct i2c_client *client,
> > >  
> > >  	tsdata->max_support_points = chip_data->max_support_points;
> > >  
> > > +	tsdata->vcc = devm_regulator_get(&client->dev, "vcc");
> > > +	if (IS_ERR(tsdata->vcc)) {
> > > +		error = PTR_ERR(tsdata->vcc);
> > > +		if (error != -EPROBE_DEFER)
> > > +			dev_err(&client->dev, "failed to request regulator: %d\n",
> > > +				error);
> > > +		return error;
> > > +	}
> > > +
> > > +	error = regulator_enable(tsdata->vcc);
> > > +	if (error < 0) {
> > > +		dev_err(&client->dev, "failed to enable vcc: %d\n",
> > > +			error);
> > > +		return error;
> > > +	}
> > > +
> > >  	tsdata->reset_gpio = devm_gpiod_get_optional(&client->dev,
> > >  						     "reset", GPIOD_OUT_HIGH);
> > >  	if (IS_ERR(tsdata->reset_gpio)) {  
> 
> You need to disable regulator here. We do not have
> devm_regulator_enable() (and Mark had some concerns about mixing managed
> and unmanaged APIs for regulators so we can't simply introduce it),
> so I'd recommend using devm_add_action_or_reset() and iunstall custom
> action to turn off regulator.

Yep, I see. Thank you about "devm_add_action_or_reset", I did not know
this function. I will add it in next version.

> 
> > > @@ -1120,20 +1138,31 @@ static int edt_ft5x06_ts_remove(struct i2c_client *client)
> > >  static int __maybe_unused edt_ft5x06_ts_suspend(struct device *dev)
> > >  {
> > >  	struct i2c_client *client = to_i2c_client(dev);
> > > +	struct edt_ft5x06_ts_data *tsdata = i2c_get_clientdata(client);
> > >  
> > >  	if (device_may_wakeup(dev))
> > >  		enable_irq_wake(client->irq);
> > >  
> > > +	regulator_disable(tsdata->vcc);
> > > +  
> > 
> > How will the touchscreen wakeup the system with interrupt if you power it off
> > on suspend? Perhaps guard this with device_may_wakeup() too?   
> 
> Exactly, it should be in an "else" branch.
> 
> Thanks.
> 

I see, I will add it in v4.

Best regards,

-- 
Mylène Josserand, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com